How to open an Excel file in C#?

Question

I am trying to convert some VBA code to C#. I am new to C#. Currently I am trying to open an Excel file from a folder and if it does not exist then create it. I am trying something like the following. How can I make it work?

Excel.Application objexcel;
Excel.Workbook wbexcel;
bool wbexists;
Excel.Worksheet objsht;
Excel.Range objrange;

objexcel = new Excel.Application();
if (Directory("C:\\csharp\\error report1.xls") = "")
{
    wbexcel.NewSheet();
}

else
{
    wbexcel.Open("C:\\csharp\\error report1.xls");
    objsht = ("sheet1");
}
objsht.Activate();

Solution 1

You need to have installed Microsoft Visual Studio Tools for Office (VSTO).

VSTO can be selected in the Visual Studio installer under Workloads > Web & Cloud > Office/SharePoint Development.

After that create a generic .NET project and add a reference to Microsoft.Office.Interop.Excel via 'Add Reference... > Assemblies' dialog.

Application excel = new Application();
Workbook wb = excel.Workbooks.Open(path);

Missing.Value is a special reflection struct for unnecessary parameters replacement

---

In newer versions, the assembly reference required is called Microsoft Excel 16.0 Object Library. If you do not have the latest version installed you might have Microsoft Excel 15.0 Object Library, or an older version, but it is the same process to include.

Solution 2

FileInfo fi = new FileInfo("C:\\test\\report.xlsx");
if(fi.Exists)
{
    System.Diagnostics.Process.Start(@"C:\test\report.xlsx");
}
else
{
    //file doesn't exist
}

Solution 3

private void btnChoose2_Click(object sender, EventArgs e)
{
  OpenFileDialog openfileDialog1 = new OpenFileDialog();
  if (openfileDialog1.ShowDialog() == System.Windows.Forms.DialogResult.OK)
  {
    this.btnChoose2.Text = openfileDialog1.FileName;
    String filename = DialogResult.ToString();

    var excelApp = new Excel.Application();
    excelApp.Visible = true;
    excelApp.Workbooks.Open(btnChoose2.Text);
  }
}

Solution 4

Imports

 using Excel= Microsoft.Office.Interop.Excel;
 using Microsoft.VisualStudio.Tools.Applications.Runtime;

Here is the code to open an excel sheet using C#.

    Microsoft.Office.Interop.Excel.Application excel = new Microsoft.Office.Interop.Excel.Application();
    Microsoft.Office.Interop.Excel.Workbook wbv = excel.Workbooks.Open("C:\\YourExcelSheet.xlsx");
    Microsoft.Office.Interop.Excel.Worksheet wx = excel.ActiveSheet as Microsoft.Office.Interop.Excel.Worksheet;

    wbv.Close(true, Type.Missing, Type.Missing);
    excel.Quit();

Here is a video mate on how to open an excel worksheet using C# https://www.youtube.com/watch?v=O5Dnv0tfGv4

Solution 5

you should open like this

        Excel.Application xlApp ;
        Excel.Workbook xlWorkBook ;
        Excel.Worksheet xlWorkSheet ;
        object misValue = System.Reflection.Missing.Value;

        xlApp = new Excel.ApplicationClass();
        xlWorkBook = xlApp.Workbooks.Open("csharp.net-informations.xls", 0, true, 5, "", "", true, Microsoft.Office.Interop.Excel.XlPlatform.xlWindows, "\t", false, false, 0, true, 1, 0);
        xlWorkSheet = (Excel.Worksheet)xlWorkBook.Worksheets.get_Item(1);

source : http://csharp.net-informations.com/excel/csharp-open-excel.htm

ruden

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Comments

[Callum Rogers]

Unless you're using VS2010 :) Oh, and you want Missing.Value

[abatishchev]

@Saravanan: See MSDN: Object ReadOnly. I guess you need to pass true.

[Saravanan]

:Please See my Question... stackoverflow.com/questions/8906670/…

[shaosh]

The excel does not show without excelApp.Visible = true. Thanks!

[Nad]

when I add that I get error as CS0104: 'DataTable' is an ambiguous reference between 'System.Data.DataTable' and 'Microsoft.Office.Interop.Excel.DataTable'

[abatishchev]

@coder: remove using System.Data; or use "using DataTable = Microsoft.Office.Interop.Excel.DataTable;

[Nad]

@abatishchev: when I remove using System.Data; i get namespace error for dataset which I am using for another set of code..

[abatishchev]

@coder: use full name (namespace.class.name) in either case

[Nad]

when I write System.Data.DataTable ObjDt = ObjPriDal.ExecuteSystem.Data.DataTable(strquery); it gives error for ExecuteSystem as DataAccessLayer does not contain a definition for ExecuteSystem

[abatishchev]

@coder: you don't need it in the right expression. Use full name as you usually declare variable's type

[Nad]

Let us continue this discussion in chat.

[Nad]

@abatishchev: I tried like this var directory = Server.MapPath("~/Attachment/"); ExcelLibrary.DataSetHelper.CreateWorkbook(directory + "Employee_lwpc_Details.xls", DS_lwpc); Microsoft.Office.Interop.Excel.Application excel = new Microsoft.Office.Interop.Excel.Application(); Workbook wb = excel.Workbooks.Open(directory + "Employee_lwpc_Details.xls", DS_lwpc)); getting error as cannot implicitly convert type Microsoft.Office.Interop.Excel to Excellibrary.office.Excel.Workbook

[ThomasMX]

@abatishchev I tested your code, it's running. I'm wondering though, how is it possible to instantiate Application when it is actually an interface?

[abatishchev]

@ThomasMX: I was wondering this for a while too. Since VSO is a COM wrapper, .NET makes it possible to instantiate an interface. Each is decorated with Guid and that's how it's being read from registry and instantiated.

[Chjquest]

private object _value = Missing.Value; replace the missing with _value. And it works for me.

[Roland]

Works for me. Certainly simpler than the accepted 2009 answer because no additional tools are needed, and it is essential a one-liner.

[Matthew]

See here for a full example of creating and saving an Excel file using the interop stackoverflow.com/a/23102523/8595398

[Eda]

Great, just what I was looking for, thanks! I simplified it by just passing the fi inside the start as System.Diagnostics.Process.Start(fi.ToString());

[shahsani]

This is by far, the most easy way to do it. Thank you